As is known, vascular catheters, including central venous catheters, or CVCs, are medical devices for the infusion of pharmacological substances and fluids into a vessel of a patient, for example, the inner jugular, the subclavian, and the femoral vein, and for performing extracorporeal blood circulation during hemodialysis or other procedures which require extracorporeal blood circulation. Such vascular catheters can include, depending upon the operating requirements, one or more lumens; single-lumen, dual-lumen and triple-lumen catheters are generally used.
The classical application of dual-lumen or triple-lumen catheters relates to extracorporeal circulation for performing chronic extracorporeal hemodialysis, such as for patients which chronic kidney failure, and for performing continuous renal replacement therapy, or CRRT, in critically ill patients in intensive care units. Single-lumen catheters are used to infuse drugs and liquids, to draw blood samples and to monitor pressures in certain vascular regions.
Catheters can be of two main types: temporary and permanent. Temporary catheters are those which are placed for limited periods of time in patients who have acute requirements, whereas permanent catheters are placed to ensure chronic therapies and can have a working life of over three years. Since permanent catheters must ensure higher safety due to their permanent nature, they are provided with a subcutaneous portion between the entrance into the vein and the exit from the skin, so as to minimize the possible infections to which the patient is exposed. Any manipulation of any kind of central venous catheter, if not performed in fully aseptic conditions, can expose the patient to even fatal infection, since the CVC is placed in a central vein. Maintenance of the catheters after each use in a medical procedure is therefore particularly important in order to avoid infections and dysfunctions thereof.
In addition to the problem of infection, catheters, by being in contact with blood, are in fact exposed to coagulation of the blood at the location of the openings of the lumens. Coagulation in the catheter lumen therefore causes malfunction thereof or even complete blockage of the catheter, with the consequent need to replace it in order to continue the medical therapies in progress. Currently, the lumen or lumens of the catheter, after each use, are washed by infusing thereinto physiological solution and are then medicated by infusing thereinto an anticoagulant in order to avoid coagulation therewithin, which anticoagulant expresses the physiological solution from the catheter lumens into the vasculature. The anticoagulant is subsequently evacuated by vacuum from the catheter's proximal end when next the catheter is to be used for hemodialysis. Since the anticoagulant must remain in place and must not enter the blood circulation of the patient, in order to avoid anticoagulation within the vasculature of the patient, the volume of anticoagulant applied to each catheter lumen used must match exactly the volume of the lumen used in the procedure.
Currently, health workers who close a catheter are required to perform the following procedures for each lumen of the catheter: open a sterile syringe; open the vial of physiological solution; aspirate the physiological solution into the syringe; disconnect the device connected to the lumen of the catheter, such as an infusion syringe or tubing for dialysis or for extracorporeal circulation in other medical contexts; connect the syringe; infuse the physiological solution to perform washing; disconnect the syringe; open another sterile syringe, open the vial of anticoagulant solution; aspirate the anticoagulant solution into the syringe, paying particular attention to the aspirated volume; connect the syringe to the catheter lumen; infuse the anticoagulant in the exact filling volume of the lumen; disconnect the syringe; and apply the closure plug to the catheter lumen.
As is evident from this sequence of operations, the maintenance procedure of a catheter is time-consuming and laborious. In view of the laboriousness, the risk of procedural errors on the part of an operator is obviously high. Typical errors can be, for example, the use of incorrect products in solution, the infusion of incorrect quantities, errors in connecting parts of the catheter, and so forth. In addition to the possibility of errors, which can lead to the need to remove the catheter or, in the worst case, to actions which damage the health of the patient, the time-related aspects of the operations that must be performed also have to be considered. The maintenance time of a catheter is in fact not negligible, and if it is necessary to perform this operation frequently, as in the case of a large number of patients, the total time is important and must be assessed in terms of management expense of the hospital ward.
The aim of the present invention is to solve the problems linked to the maintenance of vascular catheters as described above. It is desired to reduce the number of operations linked to the maintenance of vascular catheters. It is also desired to reduce maintenance time with respect to maintenance of vascular catheters.
It is also desired to provide a device for catheter maintenance that is easy to use, that is safe for the practitioner and reliable in operation, and that is flexible in its use.
It is also desired to provide such a device that enables avoidance of infection risk and of anticoagulation phenomena in the patient.